When most plastic lenses get cloudy it because the plastic is breaking down. So in order to restore, you need to remove a layer of plastic off of it. IMHO, this cannot be effectively done with these products alone.
To do it right it needs wet sanding with 1000 and 3000 grit paper, then the polish, then a sealant. However, the plastic will continue to breakdown and so it will likely need to be redone in a year or two depending on the plastic.
From a
vending perspective, I've never had much luck selling special project type products. Wipes, towels, air fresheners, tire products sell well...the rest doesn't.